Heat exchanger and a heat exchanger element therefor

Abstract

The heat exchanger element is constructed with radially disposed walls so as to sub-divide the element into flow zones with alternating zones carrying first and second heat-exchange media. The alternating zones convey the media in opposite directions to carry out the heat exchange. The walls may be of flat shape disposed in a radial pattern or may be formed of corrugated plates interspaced between flat walls.

What is claimed is: 
     
       1. In a heat exchanger having a longitudinally disposed tube for guiding one heat transfer medium therethrough, a heat exchanger element disposed coaxially of the tube, said element having a plurality of walls extending outwardly from a longitudinally disposed central area, each of said walls being connected at an inner radial end to an adjacent wall and at an outer radial end to another adjacent wall to define flow zones on opposite sides of each wall, at least every second one of said walls following each other in the circumferential direction of said heat exchanger element being corrugated and having crests running in the direction of the longitudinal axis of said heat exchanger element;   a flat wall disposed between two corrugated walls, said corrugated walls having respective crests and troughs braced against said flat walls; and   means closing alternating flow zones to the remaining flow zones to form separate flow paths for two heat exchange media on opposite sides of each wall, said means defining an inlet for one heat exchange medium from the tube and an outlet for the other heat exchange medium to and from alternating flow zones at one longitudinal end of said element, and an outlet for the one heat exchange medium and an inlet for the other heat exchange medium from and to the alternating flow zones at the opposite longitudinal end of said element whereby the two heat exchange media flow in countercurrent through said element.   
     
     
       2. A heat exchanger as set forth in claim 1 wherein said flow zones expand radially outward and are disposed between two walls immediately following each other, said crests being of increasing wave height with increasing distance from said central area while the wave length of said crests decreases. 
     
     
       3. A heat exchanger as set forth in claim 1 wherein said walls are curved in involute-fashion with each pair of adjacent walls in the circumferential direction of said element enclosing over their entire extend flow zones which are of substantially the same geometrical character transverse to the longitudinal axis of said exchanger element. 
     
     
       4. A heat exchanger as set forth in claim 1 wherein said walls are of alternating patterns; one of said patterns having corrugations in a central portion of said exchanger element parallel to the axis which rise or fall alternatingly from a mean level 0 to the height +H and -H, said one pattern terminating on one long side at the height +H and on the other long side at the height -H and a plurality of elevations following said +H corrugations outside said central portion which rise exclusively from the level 0 to the height H, said other pattern being approximately plane in the region of said center portion at the height -H and has elevations which rise outside said central portion from the height -H to the height 0, said long sides of adjacent walls alternatingly joined together over their entire length to form a tight seal. 
     
     
       5. A heat exchanger as set forth in claim 4 wherein said elevations are formed by grooves. 
     
     
       6. A heat exchanger as set forth in claim 5 wherein said grooves of the corrugated wall run toward that long side which is lower than the other long side and said grooves in said other wall run toward the other long side whereby said grooves in adjacent spaces cross each other. 
     
     
       7. A heat exchanger as set forth in claim 6 which further comprises additional grooves between said grooves which run as a continuation of said crests of said corrugated wall and which rise between the heights 0 and +H. 
     
     
       8. A heat exchanger as set forth in claim 1 wherein said walls are cut in lancet-fashion outside a center portion of said heat exchanger element. 
     
     
       9. In a heat exchanger, the combination comprising a central tube for conveying a first heat exchange medium;   an outer tube coaxially of and spaced from said central tube to define an annular space;   a plurality of first walls having flat sections disposed in involute fashion in said annular space between said tubes;   a plurality of second walls having corrugated sections disposed in alternating relation with said flat sections of said first walls, each said corrugated wall having respective crests and troughs braced against respective flat walls and disposed longitudinally of said central tube to define flow zones; and   means closing alternating flow zones to the remaining flow zones between each pair of adjacent flat walls to form separate counter flow paths, said means defining an inlet to alternating flow zones at one end of said walls communicating with said central tube to receive a flow of the first heat exchange medium therefrom and an outlet from said alternating flow zones at an opposite end of said walls to exhaust the flow of the first heat exchange medium, said means further defining an inlet at said opposite end to the remaining flow zones to receive a second heat exchange medium and an outlet at said one end to exhaust the second heat exchange medium from said remaining flow zones.   
     
     
       10. A heat exchanger comprising a central tube;   an outer tube coaxially of and spaced from said central tube to define an annular space;   a plurality of first walls having flat sections disposed in involute fashion in said annular space between said tubes;   a plurality of second walls having corrugated sections disposed in alternating relation with said flat sections of said first walls, each said corrugated wall having respective crests and troughs braced against respective flat walls and disposed longitudinally of said central tube to define flow zones;   each corrugated wall being connected to one adjacent flat wall on one side and connected to the other adjacent flat wall at the opposite side;   said walls extending beyond said tubes at each end thereof in lancet fashion with adjacent walls having elevations thereon disposed in mutually crossing relation whereby said flow zones open toward said central tube and said outer tube in alternating fashion to define an inlet to alternating flow zones at one end of said walls communicating with said central tube to receive a flow of the first heat exchange medium therefrom and an outlet from said alternating flow zones at an opposite end of said walls to exhaust the flow of the first heat exchange medium, while defining an inlet at said opposite end to the remaining flow zones to receive a second heat exchange medium and an outlet at said one end to exhaust the second heat exchange medium from said remaining flow zones.   
     
     
       11. In a heat exchanger, the combination comprising a central tube for conveying a first heat exchange medium;   a heat exchange element disposed about said tube, said element including a plurality of alternating flat walls and corrugated walls, said corrugated walls having crests and troughs extending longitudinally of said central tube to define alternating flow zones between each pair of adjacent flat walls, said walls extending beyond said tube at each end thereof in lancet fashion with adjacent walls having elevations thereon disposed in mutually crossing relation, each corrugated wall being connected to one adjacent flat wall on one side and connected to the other adjacent flat wall at the opposite side to define an inlet for the first heat exchange medium and an outlet for a second heat exchange medium to and from alternating flow zones at one lancet end of said heat exchange element and an outlet for the first heat exchange medium and an inlet for the second heat exchange medium from and to the alternating flow zones at the opposite lancet end of said heat exchange element;   a spherical section secured to said one lancet end to direct the first heat exchange medium from said central tube into alternating flow zones of said heat exchange element; and   an outer connecting tube disposed about said central tube and connected to the opposite lancet end to define an annular space for exhausting the first heat exchange medium from said heat exchange element.